Aiming at problem of low precision of close range positioning of wireless sensor networks（ WSNs）

propose a calibration-free triangle centroid localization algorithm based on received power level（ RPL）. The algorithm uses argument of radio signals RPL to replace traditional argument received signal strength indication（ RSSI）

it is applied in ranging model

combined with traditional triangle centroid localization model

so as to achieve gools of reducing ranging error

improving positioning precision. Through simulation

compare triangle centroid localization algorithm based on RPL with triangle centroid localization algorithm based on RSSI

results show that under the experimental environment

the triangle centroid localization algorithm based on RPL improves precision of 59. 02 % than the triangle centroid localization algorithm based on RSSI

positioning precision has been improved significantly.